Drilling apparatus



NOV. 28, w A

DRILLING APPARATUS Filed Dec. 22. 1951 2 Sheets-Sheet l OWWM 6 all flthrziqy Nov. 28, 1933. H. w. HALL DRILLING APPARATUS Filed Dec. 22. 1951 2 Sheets-Sheet 2 Patented Nov. 28, 1933 DRILLING APPARATUS Horace W. Hall, Newton, Mass. 7

Application December 22, 1931 Serial No. 582,568

17 claims," (01. 144-96) This invention relates to apparatus for drilling holes, and particularly for drilling-holes at an angle through the curved bow portion of rackets for playing tennis, squash and other games. v

In stringing .tennisrackets it 'is of great importance to have all of the holes on the inside of the bow in centeralinement around the bow head so that all the strings will lie in an approximately even plane, and yet the same holes and the stringing on'the outside surface of theracket bow must not be in center alinement; for this.

would result in a splitting of the wood. This necessitates drilling the string holes at an angle through the racket bow, starting at thecenter on the inside surface and coming out off center at the outside surface. 'I-Ieretofore, it has required skilled labor to do this drilling evenapproxi-mate- 1y accurate because the bow portion of the racket to be drilled is curved. It isalso absolutely necessary to have theholes on the outside of the racket'bow in ,the top portion exactly inpredetermined positions with relation to each other because channels must be cut in the wood-between said holes in orderto sink thestrings below the outside surface, and eflicient channel routing requires the use of an outside :J'ig formhav ing channel slots that will extend from one hole to another in the racket if the drilling is accurate.

Inasmuch as it has been found practically impossible to consistently do this angular drilling through the racket bow sufficiently accurate by hand, the channel routing has heretofore required skillful hand work inasmuch as 'thegouts-ide jig form could not be usedbecause the slots did not line up with the string holes.

Accordingly, one of my objects has been to provide mechanical means to position the racket with respect to the drill, so that the holes both on the inside and outside of the racket will be in predetermined positions with relationto each other, the human element playing-but a minor and simple part in this drilling operation.

Another object has been to make said mechani-.

cal means so simple andrapid in operation that an unskilled workman can operate the device and drill the holes accurately and speedily.

The foregoing and other objects which wil'llappear as the nature of the invention is better understood, may be accomplished by'a construction,

combination and operativearrangement of :parts such as is disclosed by the drawings. The nature of the invention is such as to render it susceptible to various changes and modifications, and, therefore, I am not to be limited to the construction disclosed by the drawings,;-but am-entitled adjustable brackets 19 bolted as at. 20 .to s'aid to all such changesltherefrom as scope of my claims.

In the drawings:v i Figure l is a plan View of my drilling apparatus showing'tennis racket ready to belmoyedinto engagement with the drill." g v Figure 2 is. a cross-section on the line 2 .2. pr Figure 1.

Figure 3 is a front paratus.

Figure 4 is a fragmentary view' of a portion of the outersurface of the racketbow showing the crossdirection of the stringing. Figure 5 is a crossesection. taken, on the line 5,-5 of Figure 4 showing the aiigleof the holes elevation of my showing a portion of the. inner surface of the racket bow with holes drilled therethrongh.

fall within t :0 drilled through the racket bow, and iii addition it by countersunk screws 14." 'Slidable in said runways 13 is acarriage l6 pri-zferably.v madeof metal as shown, which supports the article .to

be drilled and which has ball bearing wheels I57 1 movable in said runways loosely mounted on stubshafts l8 driven. into, the sides of said carriage 16. The normal position of. said carriage is determined. by stop mechanism consisting of channel iron runways 13 to which .a rubber bumpen- 21 is fastened as at 22, against which bumper said carriage stops on its. return-,rnoye ment away from the drill. Said carriagef16 an adjustable top 24 on which the-article to be drilled rests, which slants upwardly from front .to rear as shown in Figure ,2 of thedrawings,

said slant determining the angle at which the holes are drilled through the articles, as-the drill itself is mounted in a horizontal position." i

A pin 26 is driveninto said table gtopg24 this pin being desirable I in order to .steadythe-"article to be'drilled which is kept'incontact.with'said pin during the drilling operation. Ordinarily said carriage is moved towards the 'drill'bjpnshing the article ito be drilled against said pin. The article tobedrilledfas shown in the drawings is .a tennis racket30, although many other articles may likewise be drilled with my tus. Around the inner surface of the curved bow head of said racket 30 prick points or slight holes 31 are made which indicate the exact placeswhere the drilling should. start. In a stringed racket these holes [31 .mustfibe .in center alin ment all the way aroundthe wooden bow head, the distances they are spaced apart as termining the size and shape of the openmesh,

work of the stringing.

Surrounding'the portion to be drilled of. said racket 30 is a guide jig 32 which fits the outer 1 surface of said racket snugly, preferably with a slight tendency to cling to it. On this guide jig 32 guide marks 33 are made at particular points,-

preferably on the outer side thereof, as shown in Figure 3 of the drawings. There is a guide mark 34 preferably made on said carriage top 24' at the front thereof in alinement with the longitudinal axis of the drill stern 38 later described. Just before the drillcornmences to' cut into one of the prick points 30 the operator lines up one of the marks 33 on said guide jig 32 with said mark34 on the carriage and makes 7 certain that the drill point starts in one of said prick points 31, thereby-insuring that the drill will come out on the outside surface of .said

. racket at a predetermined point. -As will be noted at the start of the drilling operation the drill stem 38, jig guide mark 33, carriage mark 34 are in alinement with each other and with a prick point 31. Thus it is certain that each outside hole inv said racket 30 will be in a predetermined position with relation to the other holes, the marks 33 on said guide jig being the ones which determine where each outside hole shall be located longitudinally around the racket 'I have shown acenter guide line .35 on said a guide jig 32 and as the rackets are marked by a line or groove, not shown, .indicating the top center point of the bow, the operator can readily tell if the shape of the racket is correct by noticingif said two center lines are in alinement.

The guide jig 32.must be of the correct shape, of course, and if the racket also is, said two center .a stationary high speed drill 3'7, which has a drill stem 38, extending horizontally and perferably tapering to a sharp point to help the operator overcome any tendency ofthe drill to drift, thereby enabling him to start drilling each time exactly ina prick point 30. A speed of 3,090 revolutions per minute has been found suitable in this work. 7 1

Said drill 37 is supported bya common type of bearings 40 fastened to said work bench 12 by screws 41. A drill shaft 42 revolves'in said bearings .40 and extends therethroughrearwardly:into bearings 43 held to said bench 12 by screws 44. Said drill shaft 42 has a 'pulleyl 45 fixed to it on which is a belt 46, driven by some usual source of power notshown. V p In order to insure the prompt and automatic return of said carriage 16 to its normal position 7 against said bumper 21 a spring 48 is'fastened at one end to said workbench l2 and at the other end tov said carriage. 16' by screw eyes 43. Said spring 48 is put under tension when said carriage isxpushed rearwardly or towards said drill 3'7 so that when the operator releases her hold on said racket 30 said carriage -15 automatically returns to normal position.-

At the rear ofv each of'said-channel lI'OZlilllIl ways 13-is-a stop-bracket51 against which said half the'holes are drilled'in order to chored in said ledge 62,

carriage 16 contacts when it has reached a predeterminedlimit in a rearward direction which limit is determined bythe distance towards said drill said carriage 16 must bepushed in order to have said drill stem 38 drill a hole of even diameter all of the way through said. racket bow 30.

In Figure 4 of the drawings I have shown an outside portionof the racket bow showing the position thereon of the string holes 54 with relation to each other and the position of the out-. side stringing 55 which extendsdiago-nally part way across said bow. Should said holes 54 and stringing 55 be in a straightline afsplitting of the wool would result, consequently it is necessary to have these outside holes at an angle to each other. An illustration of theusual angle at which said holes 54 are drilled through the racket bow is given in Figure 5 of the drawings.

It will be noted in Figure 3 of the drawings that the guide marks 33 on said guide jig 32 extend from both edges only part way to the opposite edge. The reason for this is that each hole on the outside of the racket'30 is off center andon the opposite side of the next hole,- consequently the racket must be turned over after have them in alternate off center location. During the drilling operation the guide marks 33 which, with the racket in this position, extend to the bottom of said guide jig 32, arethe ones which are lined up with the carriage guide mark 34, this arrange-- ment being easier for the eye. 'A'fterthese holes are" drilled the racket is turned over, which places the guide marks 33 on the opposite edge at the bottom. To drill the holes at the thicker throat portion of the racket a longer. drill stem is used, and as the angle of the holes must be slighter the" angle of said carriage-top 24 is' correspondingly changed. i

In order to make venientlyfaccommodate itself to various sizes of my drilling apparatus con rackets and'other articles and to enable'theop-lerator to drill holes at various points and at difily operable by means of which the angle at which the carriage top 24slants may be changed and said top raised or lowered vertically, asfollows. 'Said carriage 16 has a base 60 supported by a 'rib 61', and'a ledge 62 integral with said base 60 extends across and projects beyond the front 63 of said carriage 16'. A shaft 641s rotatably anaportion of which shaft is threaded as at 65, and a handle 66 is fixed to the top of said shaft, the turning ofwhich raises or lowers said carriage 'top 24 vertically. A

bearing '6'! integral with said front 63.supports 'ferent angles, Iha've illustrated mechanism readlarge'ear 72 atoneside and a smaller ear '73 j fat the other side, both of which ears are sup' ported by a horizontal shaft '74 which is pivotally mounted in'said ears '72 and -73. Said shaft '74 also passes through said block '70 thereby connecting said block to said ears.

Said block '70 has an integral bracket portion 75 in which there is a curved slot '76 through which'a stub shaft '77 passes, and extends into said ear '72 being threade ed at one end into a hand wheel '78. Thetigh ening ofsaid hand wheel '78 on said stub shaft 7'7 draws the wider'outside end of said shaft against said bracket portion thereby holding it tightlyin whatever position in said slot 16 is desired. To'changethe slant or angle ofsaid carand being supported at its upper-end by a bearing 82integral with said front 163.-

What I claim is: j 1. Drilling apparatus comprising a drill, .means .to support the article to be drilled and adapted to be moved rearwardlyand having a 'guidefimark thereon, and a .guidejig adapted to surround an outer side portion of the article to be drilled, said jig guide having guide marks thereon so positioned as to be brought into alinement with :said drillcutting portion and said carriage guide mark.

v2. Drilling apparatus in combination withthe article to be drilled-comprising a drill, means to' support said article and adapted to be :moved towards said drill, a guide jig *of less height than and adapted to surround a portion of the outer side of the article to be drilled, said jig and means having guide marks thereon, adapted to be brought into alinement with the cutting. portion of said-drill, w 7

3. Drilling apparatus in combination with the article to be drilled, comprising a drill, means to support said article and adapted to be moved to bring said article into contact with said drill and having a guide mark thereon, said drill and said means being :so positioned with relation to each other as to form an acute angle, a guide jig fitted around the outside of a portion to be drilled'of said article, said 'jig having guide marks thereon adapted to be'brought into alinement with the cutting portion of said drill and said carriage guide mark.

4. Drilling apparatus in combination with the article to be drilled, comprising a drill, a carriage to support said article and adapted to be moved horizontally and having a guide mark thereon in alinement with the cutting portion of said drill, said article to be drilled having holes in its inner side therein to indicate the starting points for the drilling operation, a guide jig fitting around a portion of the article to be drilled and having guide marks thereon, said drill cutting portion, a said hole, a said carriage guide mark and a said jig guide mark being so positioned with relation to each other that all can be brought into a singl horizontal alinement.

5. Drilling apparatus in combination with a racket to be drilled, comprising a drill in horizontal position, a bench, a carriage on said bench adapted to support said racket and adapted to be moved towards said drill, the top of said carriage slanting upwardly from the front rearwardly, said carriage having a guide mark thereriage against which said racket is adapted to contact during the drilling operation, said drill, cutting portion, a said hole, said carriage guide mark and a said jig guide mark being so positioned with relation to each other that all can be brought into a single alinement.

6."' l )rilling apparatus compr ising a main supporting member, a carriage resting upon and .s'lirzlable with relationto said member, having a guide mark'thereon, a steadying pin in the front portion of and projecting above-.said carriage, a"

drill, a guide jig adapted to rest upon said carriage and having guide marks thereon, said earriage and jig guide marks being so positioned that they can be brought into alinement with each other and with said drill cutting portion,

5 V 7. Drilling apparatus comprising a main supporting member having-runways thereon,:a ear y riage adapted to slide in said-runways, the upper portion of l-said carriage slanting upwardly. from front to rear and having-a guide mark thereon,

:a drill recruited in a horizontal position, a guide jig adapted to surround a portion of the article .to be drilled and having guide marks thereon, said carriage and jig. guide marks being sonposi- 'ti'oned that theycan be brought into alinement with'rea'ch other and'with the ofsaid drillp.

"cutting. portion -.8, Drilling apparatus comprising a drill in a 7 horizontal, position, a movable carriage having .a guide mark thereon 'in' alinement with said drill cutting portion, the top surface of said car- .riage slanting upwardly from'front to rear and such a direction with relation to each other that their planes form an acute angle, and a guide jig adapted to fit around a portion of the article to be drilled, said guide jig having guide. marks thereon adapted to be brought into alinementwith'the said carriage guide mark.

10. Drilling apparatus comprising a drill in a horizontal position, a carriage adapted to be moved towards said drill and having a guide mark thereon in front of and in alinement with said drill cutting portion and having a steadying pin therein projecting above said carriage in alinement-with said guide mark, the top surface of said carriage slanting upwardly from thefront,

brought into alinement with said carriage guide marks.

11. Drillingapparatus comprising a drill in a horizontal position, a movable carriage having a guide mark thereon in alinement with said drill cutting portion, the top portion of said carriage slanting upwardly from the front rearwardly, said carriage having an opening in the top thereof into which opening said drill extends, and a guidejig iadapted to fit around a portion'of the article to be drilled, said jig having guide marks thereon so 12. Drilling apparatus comprising a drill in a horizontal position, a carriage adapted to be movedhaving a guide mark thereon in alinement with said drill cutting portion, the'top surface-of said carriage slanting upwardly from the front to .t

the rear, said carriage having an opening in the top thereof into which opening said drill extends, a

a steadying pin projecting above the top of said carriage forward .of said drill, and a guide jig adapted to fit around a portion of the article to be drilled, said jig having guide marks thereon adapted to be brought into alinement with said carriage guide mark.

v13. Drilling apparatus comprising a main supporting member having runways thereon,.a-carriage having members attached thereto which are 7 adapted 'to be moved forwardly in said runways,

the topportion of said carriage slanting upwardly from front to rear and having a guide mark thereon, a .drill mounted in a horizontal position the @cutting portion of which is in alinement with said carriage, guide mark and a guide jig adapted to surround a portion'of the article to be drilled andlhaving'guide marks thereon adapted to be brought into alinement with said carriage guide mark.

I 14, Drilling apparatus in combination with the article to be drilled, comprising a drill in a'hori- .zontal position, a carriage adapted to support s'aidarticle and adapted to be moved towards said drill, said carriage having an opening therein into which said drill extends and having a guide mark thereon'in alinement with said drill cutting portion, a guide jig fitted around the'outside of the portion to be drilled of said article. and hav-' 'ing guide'marks thereon, the top surface of said carriage slanting upwardly from front to rear at such an angle that said article contacts with the cutting portion of said drill when moved towards it, said jig guide marks, being adapted to be bebrought in alinment with said carriage guide mark.

15. Drilling apparatus comprising a drill in a horizontal position,aacarriage adapted to be moved vtowards saiddrill having'a guide mark movernent of said carriage;

thereon in alinement with said drill cutting portion, the top surface of said carriage slantingupwardly from the front towards said drill, anda said drillextends, a steadying pin fastened in said carriage and projecting above it' in a positioniforward of said drill when said carriage is in normal position, and a guide jig adapted to fit around the'outside of a portion of the article to be drilled and havingv guide marks thereon which marks are so positioned" as to be'lined up with said carriage guide mark and said'drill cutting portion, said carriage top slanting upwardly from front to a rear atsuch .anangle thatthe portion of said article to befdrille'd will come in contact withsaid drill cutting portionduring the rearward 17. Drilling apparatus comprising a dri1l,,a

carriage adapted to' be moved towards said drill having a guide mark thereon in alinement with said drill cutting portion, and a guide jig adapt' ed' to fit around the outerside of a portion of the article to be drilled, said jig having guide 1 marks on its outer side adapted to be alined with said carriage guide mark. 1 I i HORACE W. HALL. 

